Preheat oven to 220°C (425°F). To make the cauliflower bechamel, place the cauliflower in a large saucepan of boiling water and cook for 10–15 minutes or until tender. Drain and set aside. Heat the oil in a small saucepan over medium heat. Add the onion and garlic and cook for 4 minutes or until soft. Place the cauliflower, onion, garlic, milk, salt and parmesan in a blender and blend until smooth. Set aside. While you are making the bechamel, place the eggplant and sweet potato, in 3 batches, on 2 large oven trays lined with non-stick baking paper. Drizzle with oil and sprinkle with salt and pepper. Cook for 10–12 minutes or until softened. Layer a lightly greased 3-litre-capacity baking dish with half the sweet potato, half the eggplant, half the silverbeet and half the basil leaves. Spread over half the bechamel. Repeat layering with the remaining ingredients. Top with the mozzarella. Cook for 15–20 minutes or until golden. Set aside for 10 minutes before cutting. Serve with the extra basil and micro basil. Serves 4.